A known type of such a device is shown in FIG. 1 which shows that portion of the handrail which is situated at either end of the walkway and whose principle is described in Patent Application FR 2 274 523.
In that known device, the handrail comprises: handrail handholds 1 mounted on respective carriages 2 whose wheels 3 move between rollway and guideway rails 4; and a handrail element 6 constituted by a flexible link interconnecting two successive carriages 2 by passing over two direction-changing members 7, such as pulleys or cogs, carried by the axles 8 of the wheels 3 of the carriages 2 so that the flexible link element 6 folds over substantially at right angles facing each corresponding handhold 1. The two ends of each flexible element 6 are connected to respective ones of two backing carriages 9 mounted to move on rollway and guideway rails 10 which are maintained at a distance from the rollway and guideway rails 4 for the carriages 2 that varies so that the spacing between the handholds 1 varies, thereby varying their speed, i.e. the handholds 1 can move apart in an acceleration zone B situated at one end of the walkway (at the entrance end), can come closer together in a deceleration zone B situated at the other end of the walkway (at the-exit end), and can remain equidistant in a constant-speed zone between the acceleration zone B and the deceleration zone B, thereby forming a moving handrail that it is desirable to make xe2x80x9csynchronousxe2x80x9d with the moving floor of the walkway, which was not the case prior to the present invention.
Each of the sides of the moving walkway is equipped with a moving handrail, and, in the zone A in which the handrail moves at constant speed V, which zone covers most the walkway, the backing carriages 9 meet the carriages 2 carrying the handholds 1 because the guideway rails 10 are very close to the rails 4 and the flexible link elements 6 are spaced apart in a manner such that the distance between two successive handholds 1 is at its maximum. If d designates the distance from the middle of one handhold 1 to the middle of the next handhold 1, said distance varies in the acceleration and deceleration zones B. If v is the minimum speed of the handholds 1 both at the entrance to the acceleration zone B and at the exit from the deceleration zone B, and if V is the maximum speed of said handholds in the constant-speed zone A, with the ratio V/v being equal to K, the smallest value of the distance between the handholds 1 at the entrance to or at the exit from the zones B of the walkway is equal to d/K. By way of example, if, for a moving walkway, V=3 meters per second (m/s) and v=0.75 m/s, then the ratio K=4, and for d=2 meters, the minimum distance between handholds is then d/4=0.5 at the entrance to and at the exit from the walkway.
Each of the rails 4 for guiding the carriages 2 carrying the handholds 1 and each of the rails 10 for guiding the backing carriages 9 forms a loop with, at each end of the walkway a device for turning the handrail around making it possible to return the handholds from one end of the walkway to the other. In the constant-speed zone A, the rails 4 and 10 are parallel to the moving floor P of the walkway, and the handholds 1 and the flexible link elements 6 constituting the top run of the handrail are at a determined height relative to said floor. In this zone A, the backing carriages 9 are engaged in the carriages 2. In the acceleration or deceleration zone B, the backing carriages 9 roll along a portion of the guideway rail 10 that has a cam profile whose shape governs the relative movement of the successive handholds, i.e. the speed relationship that applies to them. The handrail turns around from the top run to the bottom or loop-return run by means of a circular rotation due to the circularly arcuate configuration of the rails 4 and 10, while maintaining the handholds 1 at their minimum relative distance at the exit from the deceleration zone or at the entrance to the acceleration zone.
Such a configuration suffers from the drawback of being excessively voluminous because of the large diameter xcfx86 of the circular path of the handholds as each end of the handrail turns around. It is therefore necessary to provide a relatively deep pit for receiving the turn-around end portion. For example, in the above case, when the distance between the spaced-apart handholds in the constant maximum speed zone is 2 m and becomes 0.5 m at the entrance to or at the exit from the walkway, with the distance between the handholds and the backing carriages then being 0.75 m in the turn-around zone, the diameter xcfx86 of the circular trajectory of the handholds during the turn-around is at least a minimum of 2.5 m or even 3 m, given the overall size of the successive backing carriages.
The problem posed is firstly to obtain genuine synchronization between the handrails and the moving floor of the walkway in the acceleration and deceleration zones which, for reasons of comfort and of optimizing the forces on the mechanical systems, must be zones of constant acceleration and deceleration, and secondly to overcome the above-mentioned drawback in the turn-around zones so as to minimize the turn-around height within which the handrail handholds are turned around.
The invention solves the problem posed by means of a device forming a moving handrail for an accelerated moving walkway, which handrail comprises N handholds mounted on carriages that move over at least one rollway and guideway rail, and flexible link elements of the same length L, each of which interconnects two consecutive carriages, folding over facing said carriages via a direction-changing member, and anchored at both ends to two backing carriages that move over at least one other guideway and rollway rail situated at a distance from the rail carrying the carriages that varies so as to accelerate and decelerate said carriages between a given maximum speed and a given minimum speed, each of said rails being shaped into a loop whose bottom run and top run are rectilinear and mutually parallel respectively in a bottom zone E and a top zone A corresponding to at least a portion of their length, and their end portions F are curved and serve to turn around the assemblies comprising the handholds, the link elements, and the backing carriages, the guideway and rollway rail for the backing carriages diverging, beyond the top zone A, away from the guideway and rollway rail for the carriages in a zone B situated before each end portion F of their top runs; according to the invention said rail carrying the backing carriages converges towards the rail carrying the carriages in a zone D situated between the divergence zone B and the turn-around zone F, and, in at least the divergence zone B, follows a cam outline having an oscillatory profile in which the length of each wave Bi is equal to the distance between a first one and a third one of the consecutive backing carriages, each placed at a respective end of the wave that they flank.
Preferably, at each end of each wave, the slope of the profile of the cam outline of the rail carrying the backing carriages is parallel to the slope of the segment of the rail carrying the carriages that is situated in the same transverse plane intersecting the end of the corresponding wave and perpendicular to the two rails; in addition, the number of handholds situated between the beginning and the end of each divergence zone B is odd, and, when a first handhold is positioned at one end, the last handhold is positioned at the other end of the same zone.
Since it is possible to use such a fast moving walkway of the invention in either direction of traffic flow, the zone B which is the acceleration zone in one direction naturally becomes the deceleration zone B in the other direction and vice versa. For this purpose, in the present invention, said cam outlines of the rail carrying the backing carriages are the same at each end of the handrail device at least in the divergence zone B.
In a preferred embodiment, the top run and the bottom run of the loop of the rail carrying the carriages are parallel, and the device is provided with a horizontal safety zone C situated between each divergence zone B and convergence zone D.
The result is a novel handrail-forming device which overcomes the problems posed firstly by providing all the desired comfort and safety for users of the moving walkway of the invention, and secondly by optimizing the implementation of the mechanical means by minimizing their dimensions and the forces that they need to withstand.